Thin film transistor liquid crystal displays (TFT-LCDs) play a dominant role in current flat display market due to their features of small volume, low power consumption, no irradiation and so on.
Liquid crystal displays can be classified in terms of display modes into Twisted Nematic (TN) type, In Plane Switching (IPS) type, Advanced Super Dimension Switch (ADS) type, etc. In an ADS mode liquid crystal display, a multi-dimensional electric field is formed with both an electric field produced at edges of slit electrodes on the same plane and an electric field produced between a slit electrode layer and a planar common electrode layer disposed in a different layer in the liquid crystal display, which is mainly a horizontal electric field so that liquid crystal molecules at all orientations, which are located between the slit electrodes and directly above the slit electrodes in a liquid crystal cell, can be rotated, which enhances the work efficiency of the liquid crystal and increases light transmittance.
For different applications, improved technologies of ADS include high transmittance I-ADS technology, high aperture ratio H-ADS, high resolution S-ADS technology and so on.
For a current ADS liquid crystal panel, in non-display areas around sub-pixel areas, various electrode structures such as gate lines or data lines are inevitably disposed. Since pixel electrodes and common electrodes are in different layers, electric field formed between them is influenced by electrode structures around sub-pixels, particularly by the insulating layer distributed over gate lines and data lines, causing certain attenuation to the electric field. In addition, due to the limited area of sub-pixel display areas and the planar structure of common electrodes, the strength of electric field between common electrodes and pixel electrodes is not ideal, especially the strength of electric field between edges of common electrodes and pixel electrodes is small, which influences penetration ratio of light in sub-pixel areas, and is disadvantageous to realize liquid crystal panels and display devices with high transmittance and wide viewing angle.